Grinding machine



NOV. 8, 1932. c v WALTER 1,886,994

GRINDING MACHINE Filed Aug. 28, 1929 4 Sheets-Sheet 1 HIIWIHH "Win l i i l n' "m...

llll INVENTOR [72 01105 VWZzZZar sdmwsm.

m ATTORNEY.

Nov. 8, 1932..

c. v. WALTER GRINDING MACHINE Filed Aug. 28, 1929' 4 Sheets-Sheet INVENTOR gzarles VWalier k- ATTORNEY Nov. 8, 1932.

C.; V. WALTER GRINDING MACHINE Filed Aug. 28, 1929 4 Sheets-Sheet 3 lNVENTOR gMI'M VWQZZW M1, ATTORNEY.

0. v. WALTER GRINDING MACHINE Filed Aug. 28, 1929 4 Sheets-Sheet 4 INVENTOR 671ml?! Vn hlier BY 5mm? now- .2;, M ATTORNEY Patented Nov. 8, 1932 CHARLESVi WALTER, OF'BRONXVILLEQNEW YORK GRINDING MACHINE Application filed August 28, 1929.- Serial No; 388,883;

ing abevel atthe'edge of the lens or disk;

by; a series ofgrinding operations or steps, all-of whichsteps are performed automatically and require little or no attentionon 15 the part of the operator.

A further object of my invention is toprovide amachine ofthis character wherein thesuccession of steps required for the grinding operation areelectrically controlled, as/will be more fully described hereafter.

A further objectis to provide a machine of this character which is adapted to'grind a'number of lenses or disks simultaneously.

A-further object is to provide a glass grind- 'l ing machine which will grind a plurality of glass disks orlenses of different size simultaneously.

A still further object is to provide-a glass beveling. machine of this character withan improved means whereby the angle of bevel may be changed a as desired, and particularlywhere such angle may be changed or Varied over a relatively wide range.

A further object of my invention is to prolensesor other glass disks duringthe operation of grinding.

A further object of myinvention is to provide an improved means for automatiautomatically discharging it when the grinding operation has-been completed.

A further object of my invention is to glass disk-and at the same time to round ofi oneyedge of the beveled surface so as to prevent the formation ofsharp corners or acute angles at the edge of the disk.

i F urther; objects and advantages of my in- 5 vide an improved means for holding the- I cally feeding the lens to the lens holder and provide an improved polishing wheel which is i daptedto po'lish a beiel at'the edge of a" beinga wheel ofrelatively rough or coarse vention include simplicity of construction, economy of time and efficiency of operation, ease with which the various steps of grinding may be controlled and the several adustments made, and the superiority and uniformity of the product produced.

Other objects and advantages of myinvention will appear from the following description taken inconnection with the accompanying drawings, wherein:

Figure 1 is a side elevation, partly in section and partly broken away, of a grinding machine showing one embodiment of my invention;

Figure 2 is a fragmentary top plan view of the structure shown in igure 1;

Figure 3 is a horizontal sectional view looking upward, taken on the line 3--8 of Figure 1 Figure 4 is a detail view partly in elevation and partly in section, certain of the parts shown being in section on the line 4-4= of Figure 2;

Figure 5 is anenlarged detail view of part of the structure shown in Figure 4; V

Figure dis a diagrammatic view of the electrical control for the mechanism employed to shift the grinding wheels to bring difi'erent wheels into position for grinding the lens,

Figure 7 is a top plan view of a portion of the finishing or polishing wheel, showing an improved construction for rounding off the sharp edges of the disk or lens as it is being beveled; and

Figure 8 is a detail horizontal sectional View of the structure shown in Figure 7 Referringto Figure 1 of the drawings, the machine comprises supporting frame 1, the top of which is formed as a table 2. Secured to a vertical shaft 6 extending upwardly through the table 2 are three grinding wheels A,-.B and C, which are'designed to operate on theedge of the lens successively, wheel A composition for making the initial beveling cut; wheel- B of a finer composition, and wheel 0 having an outer surface of felt or similar material required for the finishing operation. 100

in Figure 2 I show four lens or disk holder assemblies, 10, ll, 12 and 13, respectively, arranged around the peripheries of the grinding wheels, these several work or lens holder assemblies bein adapted to hold lenses or disks l5 against the particular grinding wheel which at the time is performing its grinding operation.

Each lens holder assembly comprises two posite points, these lens holders being carried by a holder assembly head 20, which is mounted to rotate about a central vertical axis 21, means being provided which constantly tends to rotate t e lens holder head in a counter clockwise direction as viewed in Figure l, will be more fully explained hereafter.

At 50 in Figure 2 1 she: supply hoppers or chutes adapted to contain lenses or other dislrs to be ground and at 51 I show discharge chutes adapted to receive the lenses which have been ground, one supply and one discharge chute cooperating with each lens holder. in the position of the iarts shown in Figure 2 a lens which has been ground has been discharged into the chute 51 from the outer one or the two lens holders siown in the lens holder assembly, the inner lens holder 21 has taken a new lens from the supply chute 50 and the lens holder assembly has been rota ed in a counter clockwise direction so as to bring the new lens into contact with one of the grinding wheels. The iirst grinding wheel to grind the lens is the bottom wheel A. After a predetermined number of grinding revolutions the shaft 6 which carries the grinding wheels is moved downward so as to move the middle wheel B into position for engagement with the lens. Again after a predetermined number of revolutions, the shaft 6 is again moved downward so to bring the finishing wheel G into pos'tion for engagement with the lens. Again after a predetermined number of revolutions the shaft 6 is raised so as to move all of the grinding wheels above the lens holder and the lens holder assembly is rotated through an angle of somewhat less than 130 about the axis 21 to such a position that the lens which has been ground is over the discharge hopper 51 and the lens holder 21 the opposite end of the assembly has been moved to the supply chute 50 to receive a lens from the chute. The raising of the wheel permits the lens holder assembly to rotate beneath the wheels to this position and while in this position the finished lens is discharged into the chute 51 and a new lens taken from the supply chute 50. vl hile the lens holders are at the supply and discharge chutes, the shaft 6 is lowered so as to bring the first grinding wheel A into position for engagement with the new lens.

- The lens holder assembly then rotates in a holders 21, located at diametrically op counter clockwise direction until the new lens is brought into contact with the grinding wheel A, from which time the cycle of operations above described is repeated.

In this description of the cycle of operations I have referred to but one of the lens holder assemblies. It will, however, be understood that each of the four or more lens holder assemblies will be simultaneously moved in a similar way and each will serve to hold its own lens against the grinding wheel which at that particular time is performing the grinding operation.

Lens holder assembly In Figure 4 I snow in detail one of the lens holder assemblies. This assembly comprises a rotatable lens holder head which carries two lens holders 21, extending outwardly from diametrically opposite points of the head. Each lens holder assembly is mounted on a vertical shaft 22 which constantly rotates in a counter clockwise direction as viewed in Figure 2.

Each lens holder comprises tubular casings in which is slidably and rotatably fitted a hollow cylindrical member or sleeve 32, form-ed with a shoulder between which and the outer end of the casing 30 is a piston which extenus inwardly oi the assembly head and projects through an opening 38 formed in a gear wheel 39, mounted to project into and rotate in the casing 30. Interposed between collar 37, secured to the piston rod and an inwardly projecting annular portion 40 of the sleeve 32 is a helical compression spring 42. Seated in the outer end of the tube 32 is a lens holding member or nozzle 44 which may be formed of rubber or other relatively soft material to form a cushion seat for the lens. Member 44 is formed with a circular opening which communicates with the interior of the sleeve 32. v

In operation the lens 15 is held against the seat 44 by suction. Spring 42 normally forces the piston 35 inwardly and creates sulficient suction to hold the lens. Means is provided for sliding the piston 35 outwardly through the sleeve 32 when it is desired to release a lens from the holder and for permitting the spring 42 to move the piston inwardly when it is desired to apply suction to hold the lens on its seat. Motion of the piston outwardly from the position shown in Figure 4 has the effect first of relieving the suction on the lens holder. Continued movement of the piston causes it to engage the shoulder 33 of the sleeve 32 and still further outward movement of the piston causes the sleeve and lens holding member 44 to move outward, thereby compressing the spring 34 located between the sleeve 32 and casing 30. Spring 42 is considerably stronger than spring 34 and when the piston 35 and sleeve 32 are released so as to be moved under the rctractive movement ofthe sleeve 32.

assesse retraction of thesleeve thereby creating considerable suction before any substantial is to permit thesuction-nozzle '44 after it has been advanced 1nto-=engage1nent w th a lens sired I may provide means for positively h'oldmgth'e nozzle lIl'liSS advancedposition until suction has been applied, as, for exam-- ple, by means of a'catchbetween the sleeve32 andcasing 30, which catch is released only after a predetermined retractive movement of thepiston 35in the sleeve 32."

Thereleasing of one lens and the grasping ofanother lens, respectively, is performed by" simultaneously moving their respective pistons first outwardly and then'inwardly. For ;this'purpose I provide a vertical rod 52 which is slidable in the, shaft 22. The upper end of the rod 52 is loosely secured to the shortarms 55 of bellcrank levers 56, pivoted at 57 to the lens holder head 20.

ed to move outwardly and engage the outer ends of'the respective pistons 35.

It will be seen that upon'lnoving the slidable rods 52 downwardly, the long arms 60 of the bellcrank levers are moved outwardly and engage the iner ends ofthe pistons. moving thepistons outwardly through the sleeves 32. This movement of the piston at the left of Figure 4 serves to relieve-the pressure inside the'sleeve 3.2.with the result that the lens 15 drops off from the seat 44 into any suitable re ceivingchute or hopper, 51. The continued downward movement of the rod 52 causes the pistons 35 to engage the shoulders 33 of the sleeves-32- in each lens-holder and further movement of the rod 52 downwardly causes each suction nozzle'44 to move outwardly a short'distance from its respective casingBO. This outward movement of the nozzle 44 at the right of Figure 4 causes this nozzle to engage alens 15' lightlvheld at the bottom of the chute 50 bv springs 64 and on the subs sequent raising of the rod 52 and withdrawal of the arms 60 from the ends of the pistons, permitsthe springs 42' to move the pistons backwardlyin the'sleeves 32, thereby causoperations just described a finished lens has been discharged from the holder at the'left hand of Figure 4 and a new unground lens has been re'ceivedby' the lens holder atthe right of this figure.

This

I The longer arms 6O offthe bellcrank levers 56 are adapt-' The machine. is, drivenxfrom an, electric motor which is connected to a shaft 101 having at one enda'be'vel gear 1% which mesheswitha gear105 splined to the vertical shaft 6', which carries the grinding wheels A, B and C.- Shaft 6 is rotated by the gear 105 and'is 'adapted to move vertically through the gear when the grinding wheels are shifted from one position to another. Also splined to the shaft 6 and adaptedto be turned thereby isa gear which meshes with four gears 112, supported ben'eaththe table-2 at points equally spaced around theaxis the shaft (3. Each of the gears "112 serves tofdrive' a-gear 114, also supported beneath thetable 2. One of the gears .114 is shown in Figure 4. Each of the gears 114 isrotatable on stationary bearing shaft 116 which extends through the table 2 and is secured in positionby a screw 117 which is screw-threaded through a bushing 118, projecting downwardly from the bottom of tlietablei. ,Gear 114 is'held on the stationary shaft 116 bymeans of a nut 120.

Surrounding theupper end of shaft 116 is a collar 122 which forms one end of an arm 123. The other end -of the arm 123 is formed with a bearing" sleeve 0170011901 125 which projects downwardly through an arcuate slot 126 in'the table 2. ,The top of the table is formed with aseat 127, the upper surface of which is, accurately machined so'as to, fornr a firm support for the bearing sleeve 125..

Rotatably mounted in the sleeve 125 is the shaft 22 which' ca'rries atits upper end a gear 130 which meshes with the gears 39 and serves to rotate'the sleeve 32 and the lens holding nozzles Secured to the lower end of the shaft 22 is a gear, 132 which meshes with the gear 114 and is driven thereby,

Gear '132 is driven ina counter clockwise direction as viewed in Figure 2. lVhen the lens holder head 20 is held against rotation in a counter clockwise direction, as, for example, "whenth'e lens 15 is in engagement with a grinding wheel, the 130 which is op-eratedfrom gear. 132 serves to rotate the gears 39 and so rotates the lens. The lens. holder head, however, is free to rotate unless held by some restraining means, the rotation of thegear 130 ina counter clockwise direction serves to maintain the lens in contact with the grindingwheel. Also,

when'the grinding wheels have been raised to theiruppermost position, they will be out of the path of the lens holder head and the lens holder head may then rotate about the axis-21 in a counter. clockwise direction and W111 continue this rotation until stopped by some obstacle interposed inits path.

Grin-{Zing wheel shift The grinding wheels are moved downwardly to 13l161fSL1CCSSlVG positions by means of a cam 180. Shaft 6 is adapted to rotate and slide in a stationary bearing 181 in the table 2 and a stationary bearing 182 in the lower partof the frame 1. The lower end of the shaft 6 rotates on a thrust ball bearing 184, carried inside a hollow slidable supporting member 186, formed at its lower end with a truncated surface 187 which is adapted to be engaged by the cam 180. Cam 180 comrises a circular plate or disk 191 which is suitably mounted to rotate in a horizontal plane and also comprises a cylindrical wall 192 of varying height which projects upwardly from the plate 191 near its periphery. The upper surface of the wall 192 forms the cam surface and engages the truncated bottom surface 187 of the member 186 to permit the grinding wheels to move downwardly by gravity to their successive positions and then to raise them. The upper surface of the wall 192 is formed with four horizontal portions, corresponding to four positions of the grinding wheels and indicated by P P P and P respectively. The upper surface of the wall 192 is inclined upwardly between the portions P and P When the truncated surface 187 is at position P the lens is being ground by wheel A and when at position P the lens is being ground by wheel B, and at position P by the finishing wheel C. At P the grinding wheels are raised above the lens holder head and while at this position the lens holder head is rotated beneath the wheels to a position to discharge a lens which has been ground and to take on a new lens from the chute 50. vVhile the supporting member 186 is riding up the longnclined surface between positions P and the operations of ejecting a lens and taking on a new one are perform-ed.

Bolted to the circular cam plate 191 at its periphery is a gear 200, which is adapted to be rotated by a worm mounted on a horizontal shaft 202. Shaft 202 carries a gear 203 which is turned by a worm 204 on a vertical shaft 205. Shaft 205 is adapted to be coupled to and uncoupled from a shaft 207 which is driven from the shaft 101 through bevel gears 209 and 210, respectively. The coupling and uncoupling of the shafts 207 and 205 are effected by an electromagnetic clutch 212.

Means is provided for controlling the circuit which serves to operate the clutch 212 so as to provide for a shifting of the grinding wheels at predetermined intervals, sufficient time being allowed for each wheel to complete its grinding operation on the lens before the wheels are shifted. Also this electrical controlling means is designed to grammatically the circuit arrangement for controlling the actuation of the clutch 212. Reference characters 220 and 221 represent two rotary ,controllers or switches. Controller220 comprises a long arcuate contact.

224 and three shorter arcuate contacts 225, 226, and 227, respectively. These contacts are formed on the bottom of the rotary cam 180, as indicated in Figure 1 and rotate with the cam. Contacts 224 and 226 are located at a greater distance from the centre of rotation than are the contacts 225 and 227. Adapted to be engaged by thecontacts 224 and 226 as these contacts rotate, is a stationary contact 230, and closely adjacent to the contact 230 and electrically connected therewith is a similar stationary contact 231.

The controller 221 comprises four arcuate contacts 235, 236, 237 and 238, respectively, which rotate about a centre 240. The contacts 236 and 238 are located at a greater distance from the centre 240 than the contacts 235 and 237. Adapted to be engaged by the contacts 235 and 237 as they rotate, is a stationary contact 242, and adapted to be engaged by the rotary contacts 236 and 238, is a stationary contact 243. Contacts 242 and 243 are electrically insulated from one another. The rotary contacts 235 to 238, inclusive, are formed on a gear 250, shown in Figure 1, which gear is rotated by means of a worm on a shaft 255, shaft 255 being driven from the shaft 101 through bevel gears 110, shaft 257, shaft 258, worm 259, and gear 260.

The current for energizing the magnetic clutch 212 is supplied from the mains 27 0 and 271, shown in Figure 6.

As shown in Figure 6, the supply main 270 is connected to the rotary contacts 235 to 238, inclusive, by a conductor 262. The main 271 is connected to both the stationary contacts 230 and 231 through conductor 264, clutch 212 and conductor 265. Extending between the two controlling switches 220 and 221 are a pair of conductors 267 and 268. Conductor 267 is connected to the stationary contact 242 of the controller 221 and this conductor is also connected to the rotary contacts 224 and 226 of the controller 220. Conductor 268 is connected to the stationary contact 243 of the controller 221 and is also connected to the rotary contacts 225 and 227 of the controller 220.

It is to be noted that the controller 221 being directly connected with the actuating shaft 101 is o erated continuously while the grinding mac ine is in operation, whereas the controller 220, which is operated from the power shaft 101 through the clutch 212, is operated only when the clutch 212 is energized. The operation of the controlling system shown in Figure 6 is as follows, assuming that the connections between the power motor and the controllers are such as to rotate the controllers in a counter clockavise direction *In-thep'osition of. the parts as shown in Figure 6, the grinding wheels are initheir top position, that is, the end 187 of [the hOIlIOWVi member 186 is resting on position 3P of. the cam 180. The wheels'are in their raised positionfand while in this position the lens-iholder heads swing under; the wheels,

i eaclrdischarging. a lens and taking on a new lens.

:It will besnoted that arcuate contact. 224

2118-5 'ust; assed out of enga ement with the :231,.-segment 225, conductor. 268, stationary contact v243, segment 236, conductor v262, .main 270. The energizingof the clutch. 212 serves to couple the shaft 205 to the shaft 207 andstartsthe rotation of the cam 180 which 3, lowers the shaft 6 and the grinding wheels until grinding wheel A comes into position forgrinding the lens. This is position P and is the position of the parts shown in :Figure 1. :Du'ringcthe rotation of thecam I 180, controller 220 is' rotated in a counter clockwise direction and as WheelA reaches its position ifor-grinding,- segment 225 of con- ;troller'22O moves out of engagement with the stationary contact 231 and the circuit 40 tthrough the; clutch-is broken. Contact 236 "of controller-221 is made suflicientlylong to maintain the circuit through the clutch dur- -ing the time that'arcuate contact 225 is mov sing in-engagement with fixed contact 231, so

=thatthe circuit through the clutch 212 will remain closed untilposition P of thecam is reached.

'When the arcuate segment 225 has passed .out'of engagementwith contact 231, the circuit through the clutchwill remain broken until segment 237 of the controller 221 has vmoved into engagement with fixed contact 242,-, at which time a circuit will be completed again through the clutch by way of conductor 7 v.264, clutch, conductor 265, contact230,contact 226, conductor 267, contact 237, conductor 262. This willserve to operate the cam and lower shaft 106 to position. P at which grinding wheel B is operating on the lens. \Vhen the 6O shaft reaches this position, segment 226 passes -'out of engagement with contact 230 and the circuit through the-clutch is again brcken. The cam 180 remains in this position for suf- 'ficientlength oftimeto permitwheel B to complete its'operationof grinding or polish- I ing the lens, at the end of which time segment 238 of controller 221 moves into engagement with contact 243, which serves to actuate the clutch and move the cam to position P at which position finishing wheel C is in position to operate on the lens. The grind ing wheels remain in their lowermost position until segment 235 again engages contact 242, at which time,'as will be readily appar- 1 cut, the clutch will be again energized and the cam will be turned so as to raise the grinding wheels to position P When the grinding wheels have been raised to a suflicicnt height,

. the lens holder heads swing under them, discharge. new lenses,'and take on new lenses.

Lens holder movement control At each end of the lens holder head 20 is slide 290 which is adjustable in a transverse direction by means of a screw 291. Each slide 290 carries a roller 294 which is adapted to engage the periphery of the grinding wheel and so, limit the counter clockwise rotation of the lens holder head during the grinding of the lens. Roller 294 is adjusted in its position relative to the lens holder head when it is desired to change from a lens of one diameter to a lens of a different diameter and this adjustment is also made when it is desiredto change the angle of bevel to be ground a? at the edge of the lens, as will be more full explained hereafter.

When the desired bevel has been ground,

ther advance of the lens toward the grinding wheel and so stop the grinding. As the lens is rotating aboutits central axis as it is being ground, the use of the roller 294 insures the formation ofa beveled lens which is exactlycircular in shape and this is true regardless of any wear of the grinding wheel during the wheel or roller 294 coming into contact -w1th the grindlng wheel serves to stop furthe grinding operation. The use of the roller 294 also insures absolute uniformity of product, each lens or disk at any one ad ustment $5.: of the machine being of exactly the same shape and size asany other disk ground at the same adjustment. Also the roller 294 cts as a safety device in case the lens holder fails to takea lens from the chute 50 and then swings toward the grinding wheel. In this case roller 294. on contact with the grinding wheel, stops the motion of the lens holder and prevents the lens holder seat from coming into contact with the wheel.

lVhen the grinding wheels have been raised .to their uppermost position and the lens hold- .er head has swung beneath the wheels, the

lens holder head is automatically stopped in position to discharge the'finished lensvand take on a new lens. WVhile in this position, rod' 52,.which operates the pistons 35, is raised and then lowered, these movements eifecting the dischargeof the old lens and taking on ofia new lens, after which operation the lens screw 330 or other suitable means.

holder head is released and permitted to turn in a counter clockwise direction into position for cooperation with wheel A.

The stopping of the lens holder head at its discharge position is controlled by a cam 300, mounted on a shaft 301, which is connected to and rotates at the same speed as gear Cam 300 serves to move a connecting rod or link 304 which is pivotally secured to an arm of a spider 305. Spider 305 is formed with a hub 306 which surrounds the shaft 6. Spider 305 has four arms at the outer ends of which are lugs 310 which project upwardly through an opening 311 in the supporting table 2. By movement of the cam 300 the four lugs 310 at the outer ends of the respective arms of the spider 305 may be moved so as to project into the path of a pin 312, carried by the lens holder head, and stop rotation of the head.

It is to be noted that one revolution of the gear 250 corresponds to one complete cycle of operations of the machine and cam 300, which rotates at the same speed as gear 250 thereby makes one complete revolution during the time of a complete cycle of grinding operations. The cam 300 is formed with inclined surfaces 316 which are so positioned as to move the lugs 310 while the lens holder head is swinging beneath the grinding wheels to such a position of the lugs that they will form an obstacle in the path of the pins 312, and, after operation of the pistons 35, these surfaces 316 of the cam 300 serveto move the lugs out of the path of the pins 312 and permit the lens holder head to turn to its grinding posit-ion.

The upward and downward movement of the rods 52 which serves to operate the pistons is effected by rotation of a cam 320, likewise mounted on the shaft 301. Cam 320 serves to operate an arm or link 322 connected to one arm of a spider 324. Spider 324 has four arms, the outer end of each of which is connected to an arm 327, pivoted to a sleeve or collar 328 which is mounted to rotate on an extension 329 of the fixed bearing shaft 1.16. Arm 327 is adapted to be rigidly secured to the sleeve 328 by a set Sleeve 328 forms one end of an arm 331, at the other end of which is formed a cam surface 335, adapted to engage a head 336, formed at the lower end of the rod 52. Arms 327 and 331 together form a bellcrank lever, which is adapted to be rotated about the axis of the bearing shaft 116. Rotation of this lever by an arm of the spider 324 in a clockwise direction as viewed in Figure 3, serves to raise the rod 52 and subsequent rotation of the bellcrank lever in a counter clockwise direction serves to lower the rod 52. Cam 320 is provided with inclined surfaces 340 which are so positioned that they effect the raising and lowering of the rod 52 at the time when the lens holder head is in its lens discharging and lens receiving position.

I also provide means which is operative whenever the grinding wheels are shifted, for retracting the lens slightly from the wheels in order that the movement of the wheels will not injure the lens. This I accomplish by means of a cam 360, which is likewise mounted on the shaft 301. Cam 360 serves to operate an arm 362, connected at one end to a spider 363, formed with four arms at the outer ends of which are upwardly projecting lugs 365. These lugs are adapted on movement of the spider 363 in a clockwise direction, as viewed in Figure 3, to engage pins 370 carried by the lens holder head and retract the lens holder head and lens from the path of the grinding wheels as they are moved vertically.

Cams 316, 340, and 360 may be angularly adjustable on the shaft 305, so as to vary their setting if occasion requires. It will of course be understood that the circuit through the clutch may be interlocked with the cam 360 so as to insure the closing of this circuit only in case the lens has been retracted from the grinding wheel, thus insuring that the vertical movement of the wheels will occur only when the lens has been retracted.

Adjiwtments for grinding beoels 0f clifieren-t angles The bearing sleeve 125 which supports the lens holder head is adjustable to different positions in the arcuate slot 126 so as to vary the angle of bevel ground at the edge of the lens. In changing the position of the lens holder head in this manner, arm 123 is rotated about the stationary bearing shaft 116 and suitable means may be employed for rigidly holding the arm 123 in its adjusted position, such, for example, as a thumb screw 380 threaded through the sleeve 122 and bearing against the upwardly projecting portion of the shaft 116.

In Figure 2 I show each lens holder assembly in a different position for grinding a different bevel, that of the lens holderassembly 13 being in position to grind a bevel of zero angle, that of assembly 12, somewhat greater angle, that of assembly 11, a still greater angle, and that of assembly 10, a yet greater angle, the last ap'ii'oximating a bevel of \Vhile I have shown the different lens holder heads at different angular positions, it will be understood that all four lens holder heads may be positioned at the same angle relative to the outer edge of the grinding wheel.

A number of adjustments are required for different set positions of the lens holder assembly, corresponding to different angles of bevel, so as to insure a proper contact of the lens and the grinding wheel and to provide for the movementand stopping ofthe lens holderhead at proper times durinw the cycle of operations.

To'provide fortheproper-scontact of the lens withthe grinding wheel at different bevel adjustment-s, thescrew 291 is employed to move the roller 294 transversely of the lens "holder'head To provide for propersetting of the cam335 at different b'eveladjustmerits, the angular position relativeto one another of the arms 327 and 331, which form the bellcrank lever operated by spider 324, is changed; this being accomplished by loosening the set screw 330, adjusting the angle between the arms and then tightening the set screw.

To provide for the proper operating engagement between the lugs 310carriedby the spider 305 with the pins 312 carried by the lens holder heads, the pins 312 are adjustable along their respective arcuate slots 390, formed in the lens holder heads Similarly to provide for proper engagement'between the lugs 365 of the pins 370 at different bevel settings, the pins 370 are adjustable in arouate slots 392 in the lens holder heads.

It will be understood, of course, that each lens holder head is provided with two pins 312 and two pins 87 0, located at opposite sides of the shaft 22, and these will each be adjusted when the angle of bevel is changed.

The finishing grinding wheel Grinding wheel C, which performs the finishing operation on the lens, preferably has a working or polishing surface, formed by a strip of felt carried by the periphery of the wheel. In Figures 7 and 8 I show one preferred form of finishing wheel, which comprises a body 400, formed at its periphery with a series of recesses 401, having walls which curve outwardly. The polishing sur face of the wheel is formed of a strip of felt 404, which is held to the outer surface of the body by means of clamping bars 405, which i may be forced into the recesses by clamping screws 407.

Betweentwo successive recesses 401 the outer or active surface of the felt is held in substantially cylindrical form between the points 408 and 409, that is, the felt follows a circle having as its centre the centre of rotation of the wheel. From the point 409 to the next succeeding recess 401 to the left the inward curvature of the felt strip increases progressively toward the bottom of the recess to the left and thence curves outwardly at the other side of the recess. The purpose of this configuration of the operating surface of the finishing wheel is to cause the wheel not only to finish off the bevel surface of the lens over its entire width, but also to round off the acute tion of the bevel surface and one side of the lens, so thatangle will not be sharp. The action of the wheelin rounding off the angle is a 3 )arent from 'Fi ure 17' follows a curve which is inclined toward t dotted lines in Figure 7 thus perm the wheels A and B, the rolls-r be r an 'le the junc- T of the in which for the purpose of illus"" have shown bydottedlines at 410 positions of the lens with respect t strip as'the wheel rotates di cated hy the arrow. It will be seen tl1.-

in position '410 the felt strip is in contact lens holder which is urging the lens toward the wheel.

Due to the fact that the felt between point-*409'and the recess at the left of axis o'fthe grinding wheel, the roller at time the lens 18 in position 4. 0 isout of contact with the grinding wheel, as is shown in lens holder head to press the acute angleof the lens against the inclined wall of the recess 40].. The roller, however, prevents any extensive movement of the lens into the recess and-avoids contact oft-he lens with and damage by thebars or wedges 405. If desired, 1 may also keep the roller 294 out of contact with the wheel C by making this wheel of somewhatgreater diameter than H adjusted for normal operation with the wheels A and B. In this case, however, lug 363 shoule be so formed as to retract the lens fromeacn of the three wheels as the wheels are shifted.

i It will be understood that suitable means to said holder, means for moving said holder so as to move the edge of said disk into grindlng engagement with said wheel, means for rotating said disk while in engagement with said wheel, and means for releasing said disk from said holder after the grinding operation is completed.

2. In a diskbeveling machine, a grinding whee a disk holder, means for feeding a disk to said holder, means for moving said holder sons to move'said disk into grinding engage ment with said wheel, means for rotating said disk while in engagement with said wheel, means for releasing said lens from said holder after the-grinding operation is completed,

and means for adjusting the machine so as to vary the angle of bevel.

3. In a lens beveling machine, a plurality of grinding wheels mounted on a sl'ial t a lens holder having means for pressing a lens into grinding contact with one wheel, means for temporarily withdrawing the lens from contact with said wheel and means for shifting said wheels while said lens is withdrawn so as to bring a second wheel into pos= ion ior grinding contact with said lens.

4. In a lens beveling machine, a plurality of grinding wheels, means for rotating said wheels, a lens holder having means for pressing a lens into grind ng contact with a wheel, means for tempera ly withdrawing the lens from a wheel and means for shifting the wheel while said lens is withdrawn so as to bring another wheel into position for grinding con tact with said lens.

5. In a machine of the character described, an inc-lined lens supply chute open at the bottom, yieldably releasable lens restraining means at said bottom, a suction operated lens holder and means for advancing said lens holder into contact with a lens at the bottom of said chute, creating suction to hold said lens and withdrawing said holder and lens from said chute.

6. In a machine for beveling lenses, a

grinding wheel, an inclined lens supply chute open at th bottom, yieldably releasable lens restraining means at said bottom, a lens holder having a suction nozzle, means for advancing said nozzle into engagement with the face of a lens held at the bottom of said chute, for applying suction to hold said lens and subs quently wit idrawing said nozzle and lens from said chute and means for moving; said nozzle toward said whe=l whereby said len. brought into grinding contact with said wheel.

ln a disk rinding machine a grinding eel, a re y le disk holder head having two disk holders, supply and discharge receptacles, and operating and controlling means for causing one of said holders to re ceive a disk from said supply receptacle and discharge a dish to said disc large receptacle and for subsequently rotating lhead so as to move said former disk into grinding contact with said wheel.

8. ln a grino ng machine, a grinding wheel, rotatable disk holder head having two disk holders comprising suction means for operating the holders to receive and discharge a disk, supply and discharge receptacles and controlling means for causing one of said disk holders to receive a di k from said supply receptacle and discharge a disk into said dischar e receptacle and for subsequently rotating said head as to move said former disk into grinding contact with said former wheel.

9. In a grinding; machine, a grinding wheel, a rotatable disk holder head having two disk holders, supply and discharge re- 

